<template>
  <view>
    <!--没有为什么-->
    <view class="my-search-container">
      <!-- 使用 view 组件模拟 input 输入框的样式 -->
      <view class="my-search-box">
        <uni-icons type="search" size="17"></uni-icons>
        <text class="placeholder">搜索</text>
      </view>
    </view>

    <view class="scoll-view-container">
      <!--左侧滑动区-->
      <scroll-view class="left-scroll-view" scroll-y :style="{height:wh+'px'}">
        <block v-for="(item,index) in cateList" :key="index">
          <view :class="['left-scroll-view-item', active === index? 'active': ' ']" @click="activeChange(index)">
            {{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!--右侧滑动区-->
      <scroll-view class="right-scorll-view" scroll-y :style="{height:wh+'px'}" :scroll-top="scrollTop">
        <view class="right-scroll-view-item">
          <view class="cate-lv2" v-for="(item,index) in cateLevel2" :key="index">
            <view class="cate-lv2-title"> / {{item.cat_name}} /</view>
            <view class="cate-lv3-list">
              <view class="cate-lv3-item" v-for="(item3,index3) in item.children" :key="index3"
                @click="gotoGoodsList(item3)">
                <image :src="item3.cat_icon"></image>
                <text>{{item3.cat_name}}</text>
              </view>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>

  </view>
</template>

<script>
  export default {
    data() {
      return {
        //这是屏幕可用高度
        wh: 0,
        //分类数据
        cateList: [],
        //选中样式变量
        active: 0,
        //二级分类数据
        cateLevel2: [],
        scrollTop: 0
      };
    },
    onLoad() {
      //获取手机机型信息
      const sysInfo = uni.getSystemInfoSync()
      //减去顶部搜索框的高度（50），整个屏幕可视高度
      this.wh = sysInfo.windowHeight - 50
      //获取左边滚动区域数据
      this.getCateList()
    },
    methods: {
      //同步写法
      // getCateList(){
      //   uni.request({
      //     url: 'https://api-hmugo-web.itheima.net/api/public/v1/categories',
      //     success: (res) => {
      //       console.log(res)
      //       this.cateList = res.data.message
      //     }
      //   });
      // },

      //异步写法，防止地狱回调问题，获取滑动一级二级菜单接口数据的方法
      async getCateList() {
        const {
          data: res
        } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status != 200) return uni.$showMsg()
        this.cateList = res.message
        //为二级分类赋值
        this.cateLevel2 = res.message[0].children
      },

      //点击事件
      activeChange(index) {
        this.active = index
        this.cateLevel2 = this.cateList[index].children
        //解决点击一级菜单切换二三级数据滑动bug的(每次点击，可以让滑轮回到顶部)
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      //调到商品清单页面的 携带参数
      gotoGoodsList(item3) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      },
    }
  }
</script>

<style lang="scss">
  .my-search-container {
    background-color: #c00000;
    height: 50px;
    padding: 0 10px;
    display: flex;
    align-items: center;
  }

  .my-search-box {
    height: 36px;
    background-color: #ffffff;
    border-radius: 15px;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;

    .placeholder {
      font-size: 15px;
      margin-left: 5px;
    }
  }

  .scoll-view-container {
    display: flex;

    .left-scroll-view {
      width: 120px;

      .left-scroll-view-item {
        line-height: 60px;
        font-size: 18px;
        background-color: #f7f7f7;
        text-align: center;

        &.active {
          background-color: #fff;
          position: relative;

          &::before {
            content: ' ';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #C00000;
            position: absolute;
            top: 50%;
            left: 0;
            transform: translateY(-50%)
          }
        }
      }
    }

    .right-scroll-view-item {

      .cate-lv2 {

        .cate-lv2-title {
          font-size: 12px;
          font-weight: bold;
          text-align: center;
          padding: 15px 0;
        }

        .cate-lv3-list {
          display: flex;
          flex-wrap: wrap;

          .cate-lv3-item {
            display: flex;
            flex-direction: column;
            align-items: center;
            width: 33.3%;

            image {
              width: 60px;
              height: 60px;
            }

            text {
              font-size: 14px;
              margin: 10px 0;
            }

          }
        }
      }
    }
  }
</style>
